载气对注入CVD法制备碳纳米管和碳纳米纤维的影响

采用注入化学蒸气沉积法，在石英管壁上制备得到了定向的多壁纳米碳管和纳米碳纤维．在相同的反应体系中，采用不同的载气，得到的碳材料的形态有较大不同．经SEM，TEM及Raman等证实，采用氩气和氮气作为载气时，得到了内部填充铁的碳纳米纤维，而且具有较好的类石墨晶体结构；用氢气作为载气时得到了中空的碳纳米管．通过控制氢气和惰性气体的比例，改变了碳纳米管的直径分布。     

碳纳米结构构建:十二烷基二甲基苄基氯化铵@氯化钠体系

碳纳米材料用途十分广泛,但其形貌的控制和制备方法的完善仍然是个研究热点和亟需攻克的难点。在此,基于阳离子表面活性剂十二烷基二甲基苄基氯化铵(DDBAC)@氯化钠(NaCl)体系成功制备了碳纳米结构（碳纳米管、纳米碳球、棒状和层状碳纳米结构）。以DDBAC为碳源。碳化过程中使用NaCl晶体分隔DDBAC的有序聚集体。结果表明,通过控制DDBAC浓度制备出不同形貌的碳纳米结构,在1倍临界胶束浓度（CMC）~5CMC下制备了球形、棒形碳纳米结构和碳纳米管,在10CMC下制备了矩形层状碳纳米结构。利用TEM、PL、Raman等手段对制备的碳纳米结构进行表征。通过TEM分析DDBAC @ NaCl体系结构的转变,建立了胶束结构的演变过程。表面活性剂浓度的增加最终使得碳纳米形态从球形碳纳米结构到层状碳纳米结构的变化。本实验结论表明了表面活性剂@盐体系是一种潜在的制备碳纳米结构的方法。     

碳纳米管的宏量制备及产业化

作为纳米材料的代表之一,碳纳米管因其独特的一维结构具备了优异的力学、电学、热学、光学和反应性能,使其在能源存储与转化、复合材料、多相催化、环境保护及生物医药等领域具有大量的应用潜力.本文总结了多种类型碳纳米管宏量制备的化学及工程原理,并对多壁碳纳米管、单壁碳纳米管、双壁碳纳米管、定向碳纳米管、超顺排碳纳米管、水平超长碳纳米管、掺杂碳纳米管、螺旋碳纳米管、碳纳米管结及碳纳米管/石墨烯杂化物的宏量制备方法进行了评述.同时,对碳纳米管产业化中新的工程问题,如工业标准、环境评估以及产业化进展进行了分析.目前,碳纳米管已经具有成千吨的产能,并广泛应用于锂离子电池电极、导电复合材料、汽车配件和体育用品等领域.尽管如此,高性能的碳纳米管的宏量制备及其配套产业化技术仍有待深入开发,产品需要进一步丰富、市场需要进一步拓展,以望形成大规模纳米产业,促进社会的可持续发展.     

氢氧化铯催化二硫醚、二碲醚与端炔反应研究

氢氧化铯催化下, 以商业THF作溶剂, 在氮气氛中二芳基二硫醚与端炔室温反应, 立体选择地生成(Z)-1,2-二芳硫基烯. 在空气氛中反应, 得到(Z)-1,2-二芳硫基烯与炔硫醚的混合物. 二芳基二碲醚与端炔反应, 不论在氮气氛中或空气氛中, 都只产生炔碲醚. 但是在氮气氛中炔碲醚的收率仅为空气氛中反应的50%, 对上述反应机理进行了讨论.     

自由基引发八甲基丙烯酸酯基笼型倍半硅氧烷在多壁碳纳米管表面的可控包覆

以FeSO4/K2S2O8为反应的引发剂,通过均相和非均相聚合体系,制备了聚八甲基丙烯酸酯基笼型倍半硅氧烷(PMMA-POSS)包覆的多壁碳纳米管核-壳型纳米杂化材料.透射电子显微镜显示,在均相体系中可以得到包覆均匀且厚度可调的多壁碳纳米管杂化材料,包覆厚度在15~25 nm,35~50 nm之间,非均相体系中得到了PMMA-POSS微球悬挂在碳纳米管侧壁的杂化材料.通过傅里叶红外光谱(FTIR)、拉曼光谱(Raman)以及热重分析(TGA)对杂化材料进行了表征,并给出了可能的包覆机理.     

欧洲聚合物联合会(EPF)第二届夏季大学“纳米结构聚合物材料”讲座

时间 :2 0 0 3年 5月 2 5～ 3 0日　地点 :意大利Ｇａｒｇｎａｎｏ(ＢＳ)讲题内容 :纳米结构材料综论 ;纳米材料模型化 ;超分子聚合物 ;控制有序纳米结构的聚合物络合物 ;树枝状大分子纳米材料 ;嵌段共聚物作为纳米材料 ;纳米结构热固性树脂 ;碳纳米管 聚合物纳米复合材料新性能 ;碳纳米管在聚合物中的应用 ;聚合物 层状硅酸盐纳米复合材料 ;纳米复合材料的流变行为 ;用溶胶 凝胶技术制备杂混化合物 ;多面体齐聚物硅倍半烷 (ＰＯＳＳ)杂化聚合物材料 ;柱状纳米材料与燃料电池 ;反应性加工制备杂化化合物 ;预成形纳米填料用于原位合成 ;生…     

碳纳米管的纯化

目前制备碳纳米管的方法很多，然而这些方法所制得的产物中除碳纳米管外常常还含有无定形碳、碳纳米粒子及催化剂颗粒等杂质，这些杂质的存在直接影响到碳纳米管的性能测试及其应用研究，因此碳纳米管的纯化研究十分必要与重要。而不同制备方法所得碳纳米管的性质以及所引入的杂质都不相同，这就增加了碳纳米管纯化研究的难度。本文结合该领域研究前沿对碳纳米管的纯化机理及方法做了系统的介绍。     

二茂铁填充的双壁碳纳米管的合成与红外光谱表征

通过气相法将二茂铁填充到双壁碳纳米管的纳米空腔内部, 制备了一种新型纳米杂化材料——二茂铁-双壁碳纳米管. 对这种纳米材料进行了高分辨透射电子显微镜结构分析与傅立叶变换红外光谱表征. 红外光谱研究结果表明, 碳纳米管管壁与内部二茂铁之间存在强的电子相互作用,并伴有电子转移.     

氧化铝/碳纳米管复合材料的制备及表征

采用聚乙烯醇对碳纳米管表面进行改性，通过化学沉淀法将Al(OH)₃均匀沉积在碳纳米管表面，然后在氮气气氛下于500 ℃煅烧2 h，制备出氧化铝/碳纳米管复合材料。采用TEM、TG、DTA、XRD、IR、氮吸附脱附(比表面积及孔结构分析)等对氧化铝/碳纳米管复合材料进行表征，结果表明:未经聚乙烯醇改性的碳纳米管，氧化铝与碳纳米管相互分离;经聚乙烯醇改性的碳纳米管，氧化铝与碳纳米管结合良好。经聚乙烯醇改性的碳纳米管表面均匀覆盖一层聚乙烯醇膜，通过聚乙烯醇的吸附作用， Al(OH)₃沉积在碳纳米管表面形成一层连续的覆盖层。     

大环轮烯的合成及其NMR谱特征

论述了大环轮烯、去氢轮烯、架桥轮烯及氮杂轮烯、氧杂轮烯、硫杂轮烯的合成方法;轮烯、去氧轮烯[4n+2]、[4n]体系以及杂原子轮烯[4n+1]、[4n-1]体系的NMR谱的特征;还介绍了近两年大环轮烯研究成果及发展趋势。     

Investigation of condensed products of graphite evaporation in an electric arc in argon and helium atmosphere

The composition of products formed in the discharge chamber at the synthesis of nanostructures by arc discharge was investigated. The fullerene soot obtained in an argon atmosphere was shown to contain at least three structural phases: amorphous carbon, fullerenes, and graphitized particles. In the process of thermal desorption, the water and oxygen adsorbed from the atmosphere, as well as carbon oxides generated at the oxidation evolve from the argon soot. By the reactivity, the fullerene black obtained in different buffer gases form a series: special helium, argon, usual helium. The cathode deposit of the arc discharge in argon, as in helium, contains multiwall nanotubes in its soft parts.     

Electrochemical production, characterization, and application of MWCNTs

The subject of this study is production of carbon nanotubes (CNTs) using an original procedure of reduction of lithium molten salts onto graphite cathode; their structural characterization and application as support material for electrocatalysts aimed for hydrogen evolution. As-produced CNTs were characterized by means of scanning and transmission electron microscopy (SEM and TEM), Raman spectroscopy, and thermogravimetric and differential thermal analysis (DTA). SEM and TEM images have shown that nanotubes are mostly of curved shape with length of 1–20 μm and diameter of 20–40 nm. Raman peaks indicate that the crystallinity of produced nanotubes is rather low. The obtained results suggest that formed product contains up to 80 % multiwalled carbon nanotubes (MWCNTs), while the rest being non-reacted graphite and fullerenes. DTA curves show that combustion process of the nanotubes takes place in two stages, i.e., at 450 and 720 °C. At the lower temperature, combustion of MWCNTs occurs, while at higher one, fullerenes and non-reacted graphite particles burn. As-produced MWCNTs were used as electrocatalyst’s support materials and their performance was compared with that of traditional carbon support material Vulcan XC-72. MWNTs have shown almost twice higher real surface area, and electrocatalyst deposited on them showed better catalytic activity than corresponding one deposited on Vulcan XC-72.     

碳环管的发现与生长机理初探

C60笼状结构的发现，极大地丰富了碳的结构化学，在进一步的研究中又发现了碳纳米管、“巴基葱”等新的结构形式．Chernozatonskil等还研究了碳环管（Tori）的独特结构，并预测其具有特别的电磁性质［1］．最近，我们在实验中观察到了可能具有这种结构的样品的透射电镜（TEM）图像，并由此探讨了它们的生长机理．样品的制备采用电弧法制C60的装置［2］，但是在纯氮气氛中进行，且在作为阳极的石墨棒外缘裹上一层铝箔，实验采用直流电弧，腔内氮气压力75kPa．放电结束后收集阴极碳棒上的沉积物与腔内的烟灰，研磨成细粉后，在稀盐酸中充…     

氮掺杂竹节状碳纳米管的催化合成

以有机胺为碳和氮源, 用催化方法合成出了含氮大管径竹节状碳纳米管. Fe/SBA-15分子筛为催化剂, 有机胺经过973 K高温裂解得到氮掺杂竹节状碳纳米管材料(CN_X). 比较了铁含量、二乙胺和六次甲基四胺原料对合成氮掺杂碳纳米管形貌和氮掺杂量的影响; 合成出氮碳比(N/C原子比)为0.26的氮掺杂竹节状碳纳米管材料.     

Functionalization and extraction of large fullerenes and carbon-coated metal formed during the synthesis of single wall carbon nanotubes by laser oven, direct current arc, and high-pressure carbon monoxide production methods

Large fullerenes and carbon-coated metal nanoparticles that are formed during the synthesis of carbon nanotubes have been functionalized by the addition of alkyl radicals and isolated by extraction into chloroform. The soluble, functionalized fullerenes have been isolated from raw single-wall carbon nanotube (SWNT) material prepared by laser oven, direct current arc, and high-pressure carbon monoxide production methods. Analyses of the extracted large fullerenes were carried out by thermogravimetric analysis, UV-vis-near-IR, laser desorption ionization mass spectrometry, and high-resolution transmission electron microscopy.     

Temperature and flow rate of NH3 effects on nitrogen content and doping environments of carbon nanotubes grown by injection CVD method

Large-scale and vertically aligned nitrogen-doped carbon nanotubes were synthesized by pyrolysis of pyridine with ferrocene as the catalysts under either pure NH3 or a mixture of NH3 and argon atmosphere using injection chemical vapor deposition method. Nitrogen content ranges from 4.8 at. % to 8.8 at. % and changes as a function of growth temperature and the flow rate of NH3. NH3 not only increases the nitrogen content of carbon nanotubes but also increases the proportion of pyridine-like N doping in the carbon nanotubes. It suggests that nitrogen concentration and nitrogen doping environments of carbon nanotubes could be controlled by changing the growth temperature or flow rate of NH3.     

煤基富勒烯烟灰萃取产物的质谱分析

用甲苯等有机溶剂对由煤制得烟灰(soot)进行索氏萃取，用时间飞行质谱及气相色谱-质谱联用（GCMS）技术对所得的萃取产物进行了分析，结果发现，煤基粗富勒烯中除含有大量的C60和C70外，高碳富勒烯（如C74、C78，C82、C84、C100及C106等）的丰度也较高。在煤基粗富勒烯的伴生副产物中存在一些含有苯环结构的芳香性碳氢化合物和少量的长烷烃化合物，由此推测煤基富勒烯的形成过程可能遵循着一条与以石墨为原料时的机制完全不同的途径。     

Nitrogen-doped multiwalled carbon nanotubes and their electrocatalysis towards oxidation of NO

Nitrogen-doped multiwalled carbon nanotubes (N-MWCNTs) were synthesized by thermal decomposition of pyridine and iron phthalocyanine over an iron catalyst in an atmosphere of ammonia. The N-MWCNTs thus obtained were analyzed by X-ray photoelectron spectroscopy. They were found to contain three types of nitrogen (N) atoms, namely pyridine-like, graphite-like, and molecular N. The effect of the pyridine-like N and the graphite-like N was investigated. The pyridine-like N is absorbing nitric oxide (NO) more easily than the graphite-like N. The N-MWCNTs with higher N content (especially the pyridine-like N) have higher catalytic activity (in terms of electrooxidation of NO) than those containing less N. The N-MWCNTs with high levels of pyridine N were incorporated into an electrode which suitable for sensing NO and for removal of NO due to its excellent electrocatalytic activity.     

骨架掺硼富勒烯的合成及表征

在富勒佛被合成后不久，Smalley等人就开始利用B、N、St等元素制备非碳富勒烯和骨架掺杂富勒烯的研究，合成出了骨架掺氮富勒佛一C59N，在质谱中观察到了微观量的骨架接棚富勒烯C。。B等［’－’］，但迄今尚未见非碳富勒烯和骨架掺棚富勒烯宏观是合成的报导．用础部分取代富勒     

Synthesis of Single‐Walled Carbon Nanotubes in a High Frequency Furnace

An alternative method for the synthesis of single‐walled carbon nanotubes (SWCNTs) is presented, which is based on the co‐evaporation of a pure graphite body and a metal catalyst (nickel). The graphite body is inductively heated in a high frequency furnace up to ~2400 °C. Characterization of the produced soot was performed using SEM, TEM and Raman spectroscopy techniques.